Naphthenate-petrolatum burn salve



3,036,953 Patented May 29, 1962 3,036,953 NAPHTHENATE-PETRGLATUM BURN SALVE Evan E. Davis, Jr., Drexel Hill, Pa.

(% Sun Oil Company, Marcus Hook, Pa.)

No Drawing. Filed Dec. 11, 1957, Ser. No. 701,973 7 Claims. (Cl. 167-58) This invention relates to a composition suitable for use as a salve for treating minor burns of the skin.

According to the invention, an excellent burn salve is prepared by compounding an alkali metal salt of petroleum naphthenic acids with petrolatum in proportions to give a suitable consistency for application to burned areas of the skin. It has now been found that such composition when applied to the skin immediately after a burn has been incurred, is effective in preventing or minimizing blistering and in alleviating pain.

In preparing a salve composition according to the present invention, petroleum naphthenic acids of high purity are neutralized with an alkali metal hydroxide, preferably caustic soda, and the resulting naphthenic acid salt is admixed with petrolatum. In the neutralization step it is preferable to employ the caustic soda in less than a stoichiometric equivalent amount in order to insure that the salve composition will not contain free sodium hydroxide which may have an irritating effect on the skin. However, an amount of caustic soda which is stoichiometrically equivalent to the naphthenic acids or which provides only a slight excess may be used without adverse cfiects. In compounding the resulting naphthenic acid salt with petrolatum, proportions within the range of 1:3 to 3:1 by weight generally should be employed. It is preferred that the naphthenic acids used have an average molecular weight within the range of 225-500, although naphthenic acids of other molecular weights can be used with beneficial efiect.

In order to obtain the best consistency for application of the salve composition to the skin, it is often desirable to incorporate in the final composition hydrocarbon wax in small amount. The wax can be either parafiin or microcrystalline wax, and it should have a melting point within the range of 125-290 F. The amount of wax employed generally should be within the range of 0.5-5.0% by weight of the final composition.

Treatment of a skin burn with the salve composition of the present invention should be done immediately after the burn is incurred. The salve preferably is applied to the burned area in two applications. First, the salve is spread over the burned area and is allowed to remain there for a relatively short time, for example, 2-3 minutes. The salve is then wiped ofi gently and a second application is made. This second application generally causes a soothing, cooling sensation. The salve is again allowed to remain on the skin for only a short time, such as 2-3 minutes, and then is wiped from the burned area. This treatment generally prevents blister formation except in cases when the salve is not applied soon enough after the burn or perhaps when the burn has been particularly severe. In any event the treatment is beneficial and helps to alleviate pain.

The following is a specific example of a salve prepared according to the present invention:

500 grams of petroleum naphthenic acids having an average molecular weight of 377 and a saponification value of 145 mg. KOH/gram are treated with 50 B. caustic soda in amount slightly less than the stoichiometric equivalent. The resulting sodium naphthenate salts are admixed with 5 00 grams of petrolatum to yield a composition suitable for use as a burn salve. If it is desired that the salve have more body, hydrocarbon wax having a melting point of 125-190" F. may be added in small amount, for example, 2% by weight of the final composition.

I claim:

1. A composition suitable as a salve for treating minor burns consisting essentially of an alkali metal salt of petroleum naphthenic acids and petrolatum in a proportion within the range of 1:3 to 3:1 by weight.

2. Composition according to claim 1 in which said salt is the sodium salt of naphthenic acids having a molecular weight within the range of 225-500.

3. A composition suitable as a salve for treating minor burns consisting essentially of an alkali metal salt of petroleum naphthenic acids and petrolatum in approxi' mately equal amounts.

4. Composition according to claim 3 in which said salt is the sodium salt of naphthenic acids having a molecular weight within the range of 225-500.

5. A composition suitable as a salve for treating minor burns consisting of an alkali metal salt of petroleum naphthenic acids and petrolatum in a proportion within the range of 1:3 to 3:1 by weight and 0.5-5.0% of a petroleum wax having a melting point within the range of l25-l90 F.

6. Composition according to claim 5 in which said salt is the sodium salt of naphthenic acids having a molecular weight within the range of 225-500.

7. A composition suitable as a salve for treating minor burns consisting of an alkali metal salt of petroleum naphthenic acids and petrolatum in approximately equal amounts and 0.5-5 .0% of a petroleum wax having a melting point within the range of 125-190 F.

References Cited in the file of this patent UNITED STATES PATENTS 2,628,187 Frohmader Feb. 10, 1953 2,775,561 Frohmader Dec. 25, 1956 OTHER REFERENCES Serial No. 340,476, Moskovits (A.P.C.), published May 11, 1943.

Gregory: Uses and Applications of Chemicals and Related Materials, vol. II, Reinhold Publ. Corp., N.Y., pp. 226-227.

McClure et al.: Am. I. Pharmacy, July 1943, pp. 263-264.

The Merck Manual, 8th Ed., Merck & Co., Rahway, N.J., 1950, p. 11109.

Bachrach: Soap, vol. 10, November 1934, pp. 21-23.

Remington: Practice of Pharmacy, 11th Ed., Mack Publ. Co., Easton, Pa., 1956, p. 623.

Frazier et al.: A Formulary for External Therapy of Skin, Chas. C. Thomas Publ., Springfield, Ill., 1954, pp. 62-65.

Van der Have: Petroleum and Its Products, Pitman and Sons, Ltd., London, 1957, June 28, 1957, pp. 382-383.

Dean: C. & E. News, vol. 23, No. 13, July 10, 1945, pp. 1164-1167.

C. & E. News, vol. 34, October 1, 1956, page 4780. 

1. A COMPOSITION SUITABLE AS A SALVE FOR TREATING MINOR BURNS CONSISTING ESSENTIALLY OF AN ALKALI METAL SALT OF PETROLEUM NAPHTHENIC ACIDS AND PETROLATUM INA PROPORTION WITHIN THE RANGE OF 1:3 TO 3:1 BY WEIGHT. 